postgresql - Split a string in characters SQL -

how can split string in characters , add new line after each character in postgresql

for example

num  desc  1    hello  2    bye  num  desc  1    h       e       l       l       o   2    b       y        e 

select num, regexp_split_to_table(descr,'') the_table order num; 

sqlfiddle: http://sqlfiddle.com/#!15/13c00/4

the order of characters not guaranteed , achieving bit complicated.

building on erwin's answer regarding problem:

select case           when row_number() on (partition id order rn) = 1 id           else null        end id_display,         ch_arr[rn] (   select *,           generate_subscripts(ch_arr, 1) rn   (     select id,             regexp_split_to_array(descr,'') ch_arr     data   ) t1 ) t2 order id, rn; 

edit:

if want single string each id, characters separated newline, can use this:

select id,         array_to_string(regexp_split_to_array(descr,''), chr(10)) data order id